Mersenne: HLLLL and HLL....
<< (High-level-language Lucas-Lehmer; how's that for a tortured acronym? :) >> Ew. I suggest calling it HL4. Compression is always a good thing! <> I have the teensiest fraction of knowledge about C (I'm trying to learn it now), but I know a little about compiling C programs. With DJGPP, you can enable cool options like -malign-double which can really speed up some programs. Is this the "alignment" that you're speaking of? Stephan Lavavej _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Contact Primenet
On Fri, 23 Jun 2000 12:40:13 + (GMT), in Mersenne_mailing_list you wrote: >There used to be an option in Test->Primenet to force a connection. >In version 20 this is gone and I miss it. Hi! It hasn't been deleted. It has been moved under advanced > manual communication. -- Bye. Lem -- 'CLOCK is what you make of it' -- _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Contact Primenet
There is an option under Advanced | Manual Communication to force a connection. It will update the computer info on the Primenet servers, send new completion dates, receive new exponents, and whatever else need be done. ~ Levi :o) P.S. If the option is disabled, it is possible that you'll have to consult the program's readme file to learn how to enable the options under the Advanced menu. - Original Message - From: "Russel Brooks" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, June 23, 2000 7:40 AM Subject: Mersenne: Contact Primenet > There used to be an option in Test->Primenet to force a connection. > In version 20 this is gone and I miss it. I often dial in for just a > couple of minutes. I would like to connect to primenet or Prime95 is > already trying, but I may not be connected long enough to use Prime95's > periodic connect attempt. > > Why was it deleted? Can it be brought back? > > Cheers... Russ _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: P-1 Testing
> I was running a double check (assigned by Entropia) and found a factor, > this is the second time that this has happened. I was just wondering about > a few things > > 1. How often does this happen? Depends on the bounds, which in turn depends on the exponent and your memory settings. The estimated probability of finding a factor is given at the beginning of the run & is typically between 0.02 & 0.05. > 2. Does the original tester still "lose" the LL-credit they originally > received. If they do then this doesn't seem fair to me, after all when > they did the LL-test we didn't have the capability to find that factor. Yes, in George's tables, but not according to PrimeNet. George's tables are recalculated each time from the list of exponents without known factors and take no account of factoring effort. PrimeNet accumulates all effort contributed "in good faith" by the user for both LL testing and factoring but does not include any credit for results submitted manually. > 3. > Is it worth going back and performing a P-1 test on all Mersenne > candidates with no known factor If we simply want to eliminate exponents as candidates for Mersenne primes, once we have a pair of matching residuals there seems no point in searching for factors. If we are interested in actually finding factors then P-1 will find factors for _some_ exponents at a lower compuational cost than ECM & should therefore be tried before ECM. But note that a large fraction of exponents will fail to succumb to either P-1 or ECM even with very heavy expenditure of effort. > 4. Or is it better just to factor them > deeper towards 2^72 Once we have trial factored to the Prime95 limit there seems lillte point in going further. For typical exponents, P-1 followed by ECM is likely (but not guaranteed) to find factors in this range with a higher frequncy in terms of factors found per CPU year. > > Just out of interest I ran P-1 testing on another couple of numbers but no > factor turned up. It only took about 3 hours for each test though... > > [Thu Jun 22 15:19:41 2000] > UID: nitro/liberator, M3200543 completed P-1, B1=4, B2=60, WW1: > 52E3BFCC [Thu Jun 22 19:00:18 2000] UID: nitro/liberator, M4056419 > completed P-1, B1=45000, B2=652500, WW1: 691E386D There are a large number of much smaller exponents which have had very little factoring effort other than trial factoring. See Eric Hahn's database of P-1 factoring effort ... http://www.mcn.org/2/ehahn/mersenne/mersenne.html Personally I think it's more interesting either to eliminate candidates before LL tests are run, or to try to find a factor for some of the smaller exponents for which no factors are known. Over the last 10 days or so I've tested 45 exponents with no known factors in the range 125,000 - 149,999 using P-1 with B1=1E6, B2=2.5E7 and have found two factors: P-1 found a factor in stage #2, B1=100, B2=2500. UID: beejaybee/Simon2, M143977 has a factor: 1660886238958203449182951 P-1 found a factor in stage #1, B1=100, B2=2500. UID: beejaybee/Simon2, M125933 has a factor: 1306727074606217680681 The runs take 1.5 - 2.0 hours each on a PIII-450. Although this success rate is a bit lower than I'd hoped for (just bad luck, I presume), it's a _lot_ better than trying to find factors of numbers in the Cunningham tables using ECM. Regards Brian Beesley _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: P-1 Database
Hello! All, I've updated the P-1 database again, adding two new lists. There are now four lists available: 1) The entire database (includes *all* tested exponents) 2) Tested prime exponents with no known factors 3) Tested prime exponents with at least one known factor 4) Tested composite exponents NOTE: Exponents with a factor found by P-1 are not listed if I don't know the bounds used for them. In addition, the exponent range between 200,000 - 500,000 is now available for reservations for further (deeper) testing... May the search be with you... Eric P-1 Database: http://mersenne.wackye.com http://www.mcn.org/2/ehahn/mersenne/ _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: Contact Primenet
Look under Advanced->Manual Communication. I believe what you are refering to is the "send new completion dates" checkbox. As indicated in the WhatsNew.Doc file New features in Version 20.0 of prime95.exe 7) The "send new completion dates" checkbox was moved from the Test/Primenet dialog box to the Advanced/Manual Communication dialog box. Does this help? Rich -Original Message- From: Russel Brooks There used to be an option in Test->Primenet to force a connection. In version 20 this is gone and I miss it. _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: Trouble with new DSL connection, Part 2
Title: RE: Mersenne: Trouble with new DSL connection, Part 2 Bob Margulies wrote: The standard advice on 2250 is to switch from RPC to HTTP protocol. I was already using HTTP protocol, so this doesn't apply. As an alternative it suggests I set up a proxy server. In order to do this, I need to create primenet.ini and supply it with the name of the proxy server domain and the proxy port number. I can obtain the server domain from a ping, but I have no idea about the port number. I am at a loss about how to proceed. Can anyone help? Did you try contacting you ISP for the proxy info? They usually have it on a web page, Because they can't handle the phone/email traffic for questions like these. Sorry if this is too obvious. -Shaun
Mersenne: Contact Primenet
There used to be an option in Test->Primenet to force a connection. In version 20 this is gone and I miss it. I often dial in for just a couple of minutes. I would like to connect to primenet or Prime95 is already trying, but I may not be connected long enough to use Prime95's periodic connect attempt. Why was it deleted? Can it be brought back? Cheers... Russ _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne Digest V1 #750
Mersenne Digest Friday, June 23 2000 Volume 01 : Number 750 -- Date: Mon Jun 19 18:00:02 2000 From: [EMAIL PROTECTED] Subject: Re: Mersenne: Prime64? Jason Papadopoulos wrote: > Moving to IA64 will be a much bigger challenge than simply rewriting > half a meg of assembly language. That's why I'm hoping the SGI open source compilers for IA-64 are decent (see http://oss.sgi.com/projects/Pro64/ ); at least in the near-term one could then simply compile one of the H (High-level-language Lucas-Lehmer; how's that for a tortured acronym? :) codes on the IA-64 and hopefully get performance at least as good as on the Alpha 21264. For instance Mlucas is already geared toward register- rich architectures (hey, I'm a greedy guy), and I've also written some extra radix-32 FFT-pass routines that yield marginal benefit on the 21264 (fewer passes through the data appear to be offset by slowdowns due to register pressure), but which should incur little or no register pressure on the IA-64. Guillermo Ballester Valor's recently announced Ylucas code is quite similar, so we can try out both the SGI Fortran-90 and C compilers for IA-64 under Linux. > Can you rearrange a real-valued FFT > to use multiply-adds as much as possible? It could cut the operation count > in half if you do, but to my knowledge no one has yet done so. Note that the 21264 has no multiply/add instruction and can do at most one FADD and one FMUL per cycle, but even so, Mlucas on 21264 gets nearly double the performance on the 21264 as Prime95 on the PII. Thus one could legitimately hope for performance that is better still on the IA-64, even without major restructuring of the source code to take advantage of the MADD instruction (or whatever it's called on the IA-64; MADD is the MIPS mnemonic). Assume the complex twiddles phase at the start of each FFT-pass data block processing run no faster with MADD than without (and this is pessimistic.) While the rest of a typical higher-radix FFT pass is dominated by adds, being able to do 2 of these per cycle (even without throwing in an extra multiply) should produce a significant speedup. I think we can gain a good idea of the potential performance from looking at the IBM Power3 processor, which similarly can do any combination of 2 FADD/FMUL/MADD per cycle - a couple of months ago Nick Geovanis compiled Mlucas (with no hardware-specific tweaks whatsoever) on such a machine and got 40-50% better per-cycle performance than on the Alpha 21264 (although the latter still beats the Power3 in terms of runtime due its much higher clock rate.) That translates to roughly 2.5-2.7 times the per-cycle performance of Prime95 on the PII, which ain't bad at all. again, the real question is how good the SGI compiler will be, but those folks have a great track record when it comes to optimizing compilers. Does anyone know when the first IA-64 systems will start shipping for the commercial market? Does anyone here know of a way of getting time on a beta system (an actual system, not a simulator) before then? Cheers, - -Ernst _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers -- Date: Mon, 19 Jun 2000 18:33:29 -0400 From: Lawrence Murray <[EMAIL PROTECTED]> Subject: Re: Mersenne: LOST NUMBERS I find it amusing that you do think a 550mhz too slow. When I started the test in september I had just upgraded my duel processor 350mhz pentium II to a state of the art duel pentium 550mhz pentium III 9 months later it's classified as inadequate. I can't wait to see what will be considered slow 9 months from now. 1gig? I wish I had this slow 2 x 550 back in 1994 when those awesome new pentium 60's came out and blew away our 486's (by the way I may be off with Year). For some of us that have 5 or 6 older computers sucking down electricity in the name of science, it is a big thing to hook them up to dial in. Since there are plenty of 10 million digit numbers to test I and it is known that it will take close to a year to test them arrangements should be made to extend the time of re-assignments of numbers that large. I have been part of gimps for almost 3 years. But its attitudes like this that make me want to save the 20-30 a month in electricity and just shut them downBut I realize that every cpu cycle does advance the cause. I may be silly but I get excited when I look in and see that the sustained throughput is over 1100 gigaflops, and that there are close to 28,000 computers working on this project. In order to keep a state of the art computer working on this project one would need to buy a new computer every 3 months. Thanks L. Murray P.S. after having those 10 million digits 9 months on my individual page it now looks naked and lonely "Brian J. Beesle
Mersenne: P-1 Testing
Hi, I was running a double check (assigned by Entropia) and found a factor, this is the second time that this has happened. I was just wondering about a few things 1. How often does this happen? 2. Does the original tester still "lose" the LL-credit they originally received. If they do then this doesn't seem fair to me, after all when they did the LL-test we didn't have the capability to find that factor. 3. Is it worth going back and performing a P-1 test on all Mersenne candidates with no known factor 4. Or is it better just to factor them deeper towards 2^72 Just out of interest I ran P-1 testing on another couple of numbers but no factor turned up. It only took about 3 hours for each test though... [Thu Jun 22 15:19:41 2000] UID: nitro/liberator, M3200543 completed P-1, B1=4, B2=60, WW1: 52E3BFCC [Thu Jun 22 19:00:18 2000] UID: nitro/liberator, M4056419 completed P-1, B1=45000, B2=652500, WW1: 691E386D regards G _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
